Please how can I obtain Ndlea certificate fast. Any suggestions to help me get it fast, heard it takes time to come out.

How long dose Thailand non immigrant visa take?

Good morning House,
I was sent a statement Letter from Austrian Embassy that they feel I have insufficient fund in my account and they believe I will not return if I travel. Am give 7 days to reply and tell them otherwise or risk visa denial.I want to know if sending another bank statement that has sufficient money and telling them I have a son here who is still tender and showing the a pic of us will do. Cause am a student and still single but have a child. What are your advice pls.